Review on DROK Waterproof Digital Voltmeter Voltage by Ernest Etienne

Revain sells several DROK digital readers. This is a small three digit blue LED display that measures DC voltage. This is a two wire module (red +V and black ground) so the measured voltage also powers the LED display. The display removes power from the circuit to light the LEDs (5 to 20mA). The LED digits are 11mm high and bright enough to be read from several meters away. Although it is advertised as a 12 volt battery meter, the product description states that the operating/measurement voltage for the LED display is 3 to 30 VDC. This means that the counter can be used in different vehicle electrical systems (e.g. 6V, 12V, 24V, etc.). The manufacturer claims it's waterproof, and it looks like the module is airtight; However, the red and black wires are attached to the back with bare screw/washer connections. I'm assuming it's fine for rain, but it probably shouldn't be submerged in water. It came in a neat little clear plastic box marked 'New' with part number X000HFN3B7. The inscription on the side of the module implies that it is made in China. As a previous reviewer pointed out, the stated dimensions (50 x 30 x 27mm) are INCORRECT. The dimensions of the recessed part of the module are 34 (W) x 19 (D) x 22 (D) mm (including the rear cable connectors). Please note that there are fastening tabs across the width on each side. The distance between the tops of the two mounting tabs is 42 mm. For assembly, the cut-out must therefore have a width of 36 to 38 mm and a length of 20 mm. Top flange dimensions 40 x 25 mm. The manufacturer gives an error of 1% (or +/- a number below 10V). I measured the 4.3v battery and 6v power supply with a DROK voltage meter and digital multimeter. The DROK reading was within the specified 1% error. I noticed that the previous reviewer made a huge mistake, so processing can vary on different devices. There is a strange cosmetic issue with this module. Other similar LED indicators I've purchased have turned off completely after a power outage. However, when the device is powered off, the seven-segment LED digits on this device are still clearly visible in white. If you're concerned about looks, they can be noticeable on a board with multiple LED displays when you turn off the power. In any case, I really like this little digital voltage display, hence the five stars.